In the transport industries (for example, the automotive, rail and aerospace industries), it is common practice to produce large, dimensionally accurate master models. These models are used by engineers for the conceptual design of individual component parts of the final product.
A known method involves a “building block” approach in which several boards are glued together to produce a rough model structure and this is then machined to form the desired shape. This approach, however, is labour intensive and requires precision operations, leading to high cost, and moreover results in a model which has bondlines at the surface, an appearance which is aesthetically undesirable.
There is thus a need in the industry for a model and method of making a model which are characterised by low cost and a smooth seamless surface free of bondlines. U.S. Pat. Nos. 5,707,477 and 5,773,047 describe a method for making prepreg parts for use in the aerospace industry where pliable solid patties prepared from syntactic epoxy material are hand-applied to a block made by stacking successive layers of aluminium honeycomb core. The entire resulting structure is then heated to effect cure of the patties. However, this approach is again labour intensive, in that it involves hand application of the pliable solid patties to the honeycomb core. It also requires heating of the entire structure in order to cure the applied patties. The resulting models are also of relatively high density.
Thus, there still remains a need for a model and a method of producing models, where the model is characterised by lower production costs, lower weight and a more uniform surface having improved smoothness and free of bondlines. Easy hand cutting and modelling, combined with machine (lathe or other forms) cuttability are desired attributes. More generally there is also such a need for a readily cuttable smooth material in application areas where wood or clay are used as modelling material, particularly where a durable surface is required which is more light weight and easier to paint.